Objective: To detect and characterize retinoblastoma susceptibility gene (RB1) mutations in tumor samples collected from Filipino patients with retinoblastoma. Methods: Six tumor samples were obtained from Filipino patients diagnosed with retinoblastoma. DNA was extracted from the tumor samples and exons 13-21 of the RB1 gene were amplified by polymerase chain reaction (PCR). PCR amplification products were subsequently purified and sequenced. Mutation detection and characterization were done by alignment of obtained sequences to the RB1 reference sequence from NCBI GenBank using Bioedit® software. The identified mutations were correlated with clinical presentation and family history. These mutations were also compared to known mutations reported in the RB1 Gene Mutation Leiden Open Variation Database (LOVD). Results: Mutations were detected in two out of the six samples. In a patient with unilateral disease and no family history, two mutations were identified: a novel CGT>AGT (Arginine → Serine) missense mutation in position c.1861 of exon 19 and a previously reported CGA>TGA (Arginine → STOP) nonsense mutation in position c. 1735 of exon 18. A possible large exonic deletion was identified in a case of unilateral disease with no family history. Conclusion We were able to identify both novel and known mutations in the RB1 gene of Filipino retinoblastoma cases using DNA sequencing techniques. These techniques may be applied to further characterize the genetic mutations of Filipino retinoblastoma cases and their families in developing a rational method of genetic testing for early diagnosis and counseling.
Retinoblastoma ; Genes, Retinoblastoma

No abstract available.
DNA* ; Genes, Retinoblastoma* ; Ploidies*

Human ; Middle Aged ; Adult ; RETINOBLASTOMA ; GENES, RETINOBLASTOMA ; EYE CANCER, RETINOBLASTOMA ; FAMILIAL RETINOBLASTOMA ; GLIOMA, RETINAL

No abstract available.
Carcinoma, Non-Small-Cell Lung* ; Genes, Retinoblastoma* ; Retinoblastoma*

There is no international classification of retinoblastoma that can satisfactorily address the need to aid in the diagnosis, therapy and the prognosis, both visual and systemic, of our retinoblastoma patients. The Reese-Ellsworth Classification, adopted in the 1950s is still the one being followed today. Its usefulness is limited to visual and systemic prognosis especially with the use of External Beam Radiation (EBR) and nitrogen mustard chemotherapy which were the only means of therapy available at those times. The Essen Classification, which was introduced later, provided only additional ocular findings that just addressed mainly the visual and systemic prognosis This modified classification is proposed to precisely meet the need of the general ophthalmologist to diagnose the tumor, get guidelines in its therapy, and have an idea of its visual and systemic prognosis. This is based on new knowledge gained about the tumor and advances in technology, which have resulted in more efficient diagnostic equipment and newer modes of therapy. The added years of follow-up also makes prognostication more reliable Hopefully also, if it is ever adopted internationally, it can make research studies done worldwide more comparable.
Human ; Aged ; Middle Aged ; Adult ; RETINOBLASTOMA ; GENES, RETINOBLASTOMA

OBJECTIVE: The aim of this study is to evaluate the role of tumor suppressor genes, p53 and Rb gene, as well as apoptosis in the carcinogenesis of ovarian epithelial tumors. And the value of these factors as prognostic markers to tell the transformation of borderline tumors to overt carcinomas is also studied. METHOD: Thirty cases of ovarian epithelial benign and borderline tumors and invasive carcinoma were used and the expression of the p53 protein and Rb gene protein were evaluated by immunohistochemical method. The apoptosis was evaluated by TUNNEL method. RESULTS: Positive rate of p53 expression in benign, borderline and invasive tumors were 0, 28, and 94 %, respectively. And also, p53 was highly expressed in chemoresistant cases (2/3), in residual tumor (4/5) and in recurred cancer (2/2). Rb protein was partly lost in the borderline tumors, but the rate of Rb protein loss in both borderline tumors and invasive carcinomas were similar. Apoptosis were more active in overt carcinomas than in borderline and benign tumors. In borderline tumors, p53 protein was expressed as 28.6% positivity, and apoptosis was expressed as 28.6% negativity, which showed indirectly that there was apoptosis induction effect of p53. In ten cases of invasive carcinomas showing highly expressed p53, apoptosis revealed all positive reaction except 2 cases, and Rb protein revealed variously. This result supported the apoptosis imduction effect of p53, but it was difficult to find the association of expression degree between the two tumor supressor genes CONCLUSION: In conclusion, the values of p53 is a discriminating factor of malignancy from benign and the expression of p53 is related with clinical aggressivity such as recurrence and residual cancers. Apoptosis are more active in overt carcinoma than in benign & borderline tumor, and in borderline tumor the expression of p53 is related to apoptosis induction which results to carcinomatous change.
Apoptosis* ; Carcinogenesis ; Genes, Retinoblastoma* ; Genes, Tumor Suppressor ; Neoplasm, Residual ; Recurrence ; Retinoblastoma Protein

OBJECTIVES: Recently, the studies for oncogene and tumor marker have been actively performed to investigate the carcinogenesis of gastric carcinoma, but it is not clearly understood. We investigated the expression of tumor suppressor gene and proliferation activity in gastric carcinoma. METHODS: Immunohistochemistry for p53 protein (wild and mutant type), retinoblastoma protein(wild type), and PCNA was performed in 131 cases of formalin fixed paraffin embedded tissue sections of gastric carcinoma. We compared that expression with tissue invasiveness, lymph node metastasis, staging and, Lauren classification, and that expression with each other. RESULTS: 1) The positive ratio of p53 protein, Rb protein, also PCNA in gastric carcinoma was 64.9%, 98.5%, 99.2%, 2) The expression of p53 protein was related to invasiveness, lymph node metastasis, staging, and Lauren classification(p<0.05). 3) The positive reaction for Rb gene was identified in tumor cells as well as proliferating cells. 4) There was a close relationship between Rb gene expression and PCNA in gastric carcinoma (p<0.05). CONCLUSION: Theses results suggested that the expression of p53 gene is related to invasiveness, lymph node metastasis, staging and Lauren classification in gastric carcinoma. Expression of retinoblastoma gene is a closely related to proliferating activity.
Carcinogenesis ; Classification ; Dronabinol* ; Formaldehyde ; Genes, p53 ; Genes, Retinoblastoma ; Genes, Tumor Suppressor ; Immunohistochemistry ; Lymph Nodes ; Neoplasm Metastasis ; Oncogenes ; Paraffin ; Proliferating Cell Nuclear Antigen* ; Retinoblastoma ; Retinoblastoma Protein

The formation and malignant progression of gliomas are generally considered to undergo multistepped process like other tumors. Loss of 13q is implicated in the later stage of progression of gliomas. The retinoblastoma susceptibility gene(RB gene), located at the 13q14, is a prototypic tumor suppressor gene. Many kinds of tumors are noted to have mutations of the RB gene. To determine whether the loss of 13q is associated with RB gene or not, and to find the intragenic mutation of RB, we examined 28 gliomas for loss of heterozygosity(LOH) at the RB locus using a polymerase chain reaction-based restriction fragment length polymorphism(PCR-based RFLP) assay. We found LOH in 13 of 28(46%) gliomas. Eight of 12(67%) high-grade astrocytomas, 3 of 6(50%) differentiated astrocytomas showed LOH. And we also detected LOH in 1 of 2 anaplastic oligodendrogliomas and in 1 of 7(14%) differentiated oligodendrogliomas. When we classify them into low-grade and high-grade gliomas, 4 of 14(29%) low-grade gliomas, and 9 of 14(64%) high-grade gliomas showed LOH, PCR-SSCP analysis was performed on exon, 8, 14, 15, 16, 19, 20, 21, 22, 24 to find mutations in remaining allele, and one case of mobility shift was identified in glioblastoma multiforme which showed LOH in PCR-based RFLP study. Our results demonstrate that RB deletions are detected in both low-grade high-grade gliomas, and unlike the p53 gene, genetic alterations of the RB gene in gliomas are mainly deletions rather than point mutations.
Alleles ; Astrocytoma ; Exons ; Genes, p53 ; Genes, Retinoblastoma* ; Genes, Tumor Suppressor ; Glioblastoma ; Glioma* ; Humans* ; Loss of Heterozygosity ; Oligodendroglioma ; Point Mutation ; Polymorphism, Restriction Fragment Length ; Retinoblastoma*

The risk of radiotherapy-related secondary cancers in children with constitutional retinoblastoma 1 (RB1) mutations has led to reduced use of external beam radiotherapy (EBRT) for RB. Presently, tumor reduction with chemotherapy with or without focal surgery (chemosurgery) is most commonly undertaken; EBRT is avoided as much as possible and is considered only as the last treatment option prior to enucleation. Nevertheless, approximately 80% of patients are diagnosed at a locally advanced stage, and only 20-25% of early stage RB patients can be cured with a chemosurgery strategy. As a whole, chemotherapy fails in more than two-thirds of eyes with advanced stage disease, requiring EBRT or enucleation. Radiotherapy is still considered necessary for patients with large tumor(s) who are not candidates for chemosurgery but who have visual potential. When radiation therapy is indicated, the lowest possible radiation dose combined with systemic or local chemotherapy and focal surgery may yield the best clinical outcomes in terms of local control and treatment-related toxicity. Proton beam therapy is one EBRT method that can be used for treatment of RB and reduces the radiation dose delivered to the adjacent orbital bone while maintaining an adequate dose to the tumor. To maximize the therapeutic success of treatment of advanced RB, the possibility of integrating radiotherapy at early stages of treatment may need to be discussed by a multidisciplinary team, rather than considering EBRT as only a last treatment option.
Child ; Child, Preschool ; Eye Neoplasms/genetics ; Genes, Retinoblastoma/genetics ; Humans ; Radiotherapy Dosage ; Retinal Neoplasms/*radiotherapy ; Retinoblastoma/genetics/*radiotherapy

PURPOSE: To investigate the prognostic role of apoptosis and to evaluate the relationship between apoptosis and apoptosis-related genes, as well as cell proliferation in renal cell carcinoma (RCC). MATERIALS AND METHODS: Apoptosis was detected by using the terminal deoxynucleotidyl transferase (TdT) mediated dUTP nick-end labeling (TUNEL) technique in 67 formalin-fixed and paraffin-embedded RCC specimens. Immunohistochemical stainings for p53 and retinoblastoma (Rb) proteins and proliferating cell nuclear antigen (PCNA) were also conducted simultaneously. RESULTS: The apoptotic index (AI) varied from 0.2% to 25.5%. The PCNA index (PI) ranged from 2.1% to 70.3%. The expression of p53 protein was found in 31 of 67 (46.3%) cases. Abnormal expression of Rb was seen in 23 of 67 (34.3%) cases. There was a statistically significant positive correlation between AI and increasingnuclear grade (p<0.001). A significant correlation was found between AI and PI (r=0.329, p<0.01). When comparing the AI with the expression of p53 and Rb proteins, there was no significant difference. In univariate survival analysis, nuclear grade, TNM stage, PI, expression of Rb and AI were significantly associated with shortened survival. However, TNM stage was the only independent prognostic factors by multivariate analysis. CONCLUSION: The present findings indicate that apoptosis in RCC is closely associated with cell proliferation, but not with the expression of p53 and Rb proteins. In multivariate analysis, the AI does not carry an independent prognostic significance.
Apoptosis* ; Carcinoma, Renal Cell* ; Cell Proliferation* ; DNA Nucleotidylexotransferase ; Genes, vif ; Multivariate Analysis ; Proliferating Cell Nuclear Antigen ; Retinoblastoma ; Retinoblastoma Protein